Revealing mistake: In this episode the aliens with the help of 'turncoat' Turner have frozen a moment in time in which they will attack and destroy SHADO HQ. Everything and everyone is frozen in place - except for the guy in the background walking across the road during Straker's and Turner's 'car' chase in the 'Harlington/Straker' go carts.
Continuity mistake: A UFO crash lands in Canada and sits amidst trees in a wooded area. Just before the craft explodes, the only snow visible is on mountains in the distant background. After it explodes, however, the ground and trees all around it are suddenly covered with snow. (00:36:30)Jean G
Revealing mistake: "Computer Affair": In the interior shots of Mobile 1's cockpit, we see that there's a crew of 3 and that the pilot is black. But in shots of the exterior (miniature model stock footage), there's only one occupant, a pilot, and it's a doll with distinctively Caucasian features. (00:26:30)Jean G
Plot hole: "Psychobombs": The alien-possessed Mason steals Captain Lauritzen's fingerprints by pressing his fingertips to the captain's and "heat transferring" the prints. Big problems here: those prints would now be backwards and for the wrong hand. But when the computer later reads the prints, it fails to notice this and passes him through security as "Identity Correct." (00:23:30)Jean G
Revealing mistake: "Exposed": Another piece of stock footage used throughout the series was a shot of the shiny metal sign for Harlington-Straker Studios. The clock on the side of a building is reflected in the sign's surface, always showing the same time of day - so it's 1:50 every time Straker drives by. (00:24:00)Jean G
Continuity mistake: "Kill Straker": When Straker grabs the gun from Foster, we can see a man in a spacesuit outside Moon Base's control room window. But in an establishing shot just before this, we saw an exterior shot of the base, including that window, and the spacesuited man was nowhere in sight. (00:30:00)Jean G
Factual error: "Responsibility Seat": Moon Base is imperiled by a rogue Russian mining trawler said to be heading "straight for it." But several shots of the vehicle show it veering wildly in very wide arcs, moving far too erratically to determine that it's on a collision course. (00:38:00)Jean G